1. FIELD OF THE INVENTION
The present invention is directed to a coated transparent substrate, which comprises, on at least one of its sides, a multi-layer layer-system. More specifically, the invention is directed to such a transparent substrate where the multi-layer layer-system is also transparent and the coated substrate is thus for instance a window substrate as e.g. for vehicle windows and especially for motor vehicle front windows.
The present invention is further directed on a method for producing at least one layer on a workpiece by means of a reactive deposition process, to a method for coating a workpiece with at least two layers of different materials, to an apparatus for producing at least one layer on a workpiece and finally to a Hafnium-Oxynitride.
2. DEFINITIONS
The following terms are used throughout the description and claims of the present invention:
Spectral range of visible light PA0 Spectral range of sunlight PA0 Spectral range of near (or low) infra-red light PA0 Coefficient of reflectance R.sub.vis PA0 Coefficient of transmittance T.sub.vis : PA0 Coefficient of transmittance T.sub.sun : PA0 Coefficient of reflectance R.sub.SUN : PA0 Extinction coefficient k:
Spectral range according to a light wave-length A of 380 nm to 780 nm.
Spectral range according to a wave-length .lambda. of 200 nm to 2500 nm.
Spectral range according to a wave-length A of 780 nm to 1200 nm.
The ratio of reflected to impinging light, weighed by the spectral sensitivity of the human eye: ##EQU1## wherein: R(.lambda.) is the value of reflection at a specific wavelength .lambda.,
V(.lambda.) is the spectral sensitivity of the human eye, PA1 S(.lambda.) is the spectral distribution of the standard light D65 (colour temperature 6500 K.). PA1 has a reduced sun energy transmittance T.sub.SUN, PA1 which acts anti-reflective in the visual spectral range and thus has low R.sub.vis -values and PA1 is wear (including abrasion) resistant. PA1 at light of a wave-length of 400 nm, an index of refraction of 2.7 and simultaneously an extinction coefficient k of 0.01 at the most; PA1 at light of 800 nm wave-length, an index of refraction of 2.55 and simultaneously an extinction coefficient k of 0.005 at the most and PA1 at light of 1000 nm wave-length, an index of refraction of 2.53 and simultaneously an extinction coefficient k of 0.001 at most.
The ratio of transmitted to impinging light weighed by the spectral light sensitivity of the human eye: ##EQU2## wherein T(.lambda.) is the transmittance value at a specific wavelength .lambda..
The ratio of transmitted and impinging light weighed with the spectral distribution of sun light. ##EQU3## wherein S.sub.s (A) is the spectral distribution of sun light.
The ratio of reflected light and impinging light weighed with the spectral distribution of sun light. ##EQU4## wherein A(.lambda.) is the value of absorption at a specific wavelength .lambda..
When light with a wave-length .lambda. and with the intensity I.sub.o is transmitted through a material of the thickness d, there results, at the output side, the intensity EQU I=I.sub.o .multidot.e.sup.-.alpha.(.lambda.).multidot.d
wherein there is valid ##EQU5##